In many imaging systems, such as imagesetters or platesetters, a movable optical carriage is used to displace a laser system or other imaging source in a slow scan direction along a media support surface (e.g., internal drum) to expose a supply of recording media supported on the media support surface. Generally, the imaging source includes a beam deflection assembly, comprising a deflector element (e.g., a mirror) and a spin motor for rotating the deflector element. The beam deflection assembly deflects an imaging beam generated by a radiation source across the recording media. Such an imaging system is described, for example, in U.S. Pat. No. 5,598,739, assigned to Agfa Corporation, incorporated herein by reference.
As known in the art, imaging systems are commonly equipped with internal punches that are configured to punch a predetermined set of registration openings (e.g., holes, notches, etc.), into the recording media being imaged. By registering (i.e., aligning) the recorded image to the set of holes in the recording media, accurate registration throughout the prepress process can be achieved.
The recording media to be imaged by an imaging system is commonly supplied in web form. The recording media, which may comprise a photosensitive, radiation sensitive, thermally sensitive, or other type of imageable material, is typically wound around the core of a supply roll that is mounted on a rotatable support shaft. The rotatable support shaft may comprise a portion of a media supply cassette. During the loading of the recording media onto the media support surface, a section of the web of recording media is drawn from the supply roll and is positioned on the media support surface.
Currently available systems for mounting and positioning the supply roll on a support shaft are expensive to machine and produce, have a high part count, and are difficult to use. Further, it is often difficult to accurately, repeatedly, and/or adjustably position the supply roll in a desired location on the support shaft (e.g., relative to the punches of the imaging system) using known supply roll mounting techniques.